Transaction cards with discontinuous metal strata

ABSTRACT

A transaction card having a discontinuous metal stratum with a desired degree of electrical eddy current disruption disposed on a surface of a first layer, such as a glass or other transparent layer. A transaction module disposed in the first layer is electrically isolated from the discontinuous metal stratum. The discontinuous metal stratum may include a plurality of isolated metal features that form a halftone pattern, such as a pattern that is visibly opaque to the naked eye.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No.63/032,911, filed Jun. 1, 2020, entitled TRANSACTION CARDS WITHDISCONTINUOUS METAL STRATA, the contents of which are incorporatedherein by reference in their entireties for all purposes.

BACKGROUND OF THE INVENTION

Transaction cards comprising glass have been described in numerouspatents and applications, including but not limited to U.S. Pat. Nos.9,269,032 and 8,756,680. Likewise, transaction cards comprising metalhave been described in numerous patents and applications, including butnot limited to U.S. Pat. No. 9,390,366. One design consideration formetal cards having a contactless or dual interface transactioncapabilities, is that the metal in the metal layer tends to createelectromagnetic interference that may affect operability in thecontactless mode. One advantage of a metal card is the overall weight,look and feel of the card, which is desired by consumers. While the U.S.Pat. No. 9,390,366 provides one construction that maximizes contactlessoperability while maintaining the desirability of metal, there remains aneed in the field for development of cards with unique aesthetic appeal,maximized operability, and efficient manufacturing cost.

While various combinations of metal and glass layers in transactioncards have been disclosed, such as in U.S. Pat. No. 8,725,589, thecombination of metal and glass provides unique opportunities for newconstructions to meet the continued desire in the field formetal-containing cards with unique aesthetics and maximized operabilityin contactless mode.

SUMMARY OF THE INVENTION

One aspect of the invention comprises a transaction card, comprising atleast a first glass layer, a discontinuous metal stratum disposed on afirst surface of the glass layer and having a desired degree ofelectrical eddy current disruption, and a contact, contactless, or dualinterface transaction module disposed in the first glass layer andelectrically isolated from the discontinuous metal stratum.

In one embodiment, the discontinuous metal stratum may comprise a metallayer having a plurality of discontinuities, which discontinuities mayform a pattern, such as a halftone pattern, in which the plurality ofdiscontinuities may be configured to avoid synchronization of eddycurrents of adjacent metal regions in the presence of less than apredetermined level of energy, such as a maximum rated field strength ofa contactless transaction card reader.

In another embodiment, the discontinuous metal stratum may comprise aplurality of isolated metal features, which may form a pattern, such asa halftone pattern, in which each of the plurality of metal features isseparated from adjacent metal features by at least a predeterminedminimum distance, such as a distance calculated to avoid bridging ofenergy between adjacent halftone dots in the presence of less than apredetermined level of energy, such as a maximum rated field strength ofa contactless transaction card reader.

The halftone pattern in the discontinuous metal stratum may comprise theplurality of metal features or discontinuities evenly distributed acrossthe first surface of the card, or the halftone pattern may comprise theplurality of metal features, plurality of discontinuities, or acombination thereof having an uneven distribution, wherein the unevendistribution forms a halftone image. The halftone pattern may include acombination of metal features and non-metal features. In someembodiments, the halftone pattern forms a discontinuous layer that isperceived perceptible to by the human eye as a continuous opaque layer.

Some embodiments may comprise a second layer of glass. In suchembodiments, the discontinuous metal stratum may be disposed between thefirst glass layer and the second glass layer. A metallized boosterantenna may be disposed on a surface of the second glass layer,electrically isolated from the discontinuous metal stratum on the firstlayer of glass, and coupled to or configured to couple to the paymentmodule. In some embodiments, the metallized booster antenna may bedisposed on an inner surface of the second glass layer arranged betweenthe first glass layer and the second glass layer, such as with anelectrically isolating (e.g. non-metal) layer disposed between thediscontinuous metal stratum and the metallized booster antenna. In otherembodiments, the metallized booster antenna may be disposed on an outersurface of the second glass layer facing away from the first glasslayer.

In still other embodiments, the discontinuous metal stratum is disposedon a first outer surface of the first glass layer, and the metallizedbooster antenna is disposed on a second outer surface of the first glasslayer.

A protective coating may be disposed over the metallized antenna. Themetallized booster antenna may be transparent, such as an antennacomprising indium tin oxide (ITO).

An electrical isolating material may be disposed between adjacent metalfeatures in the discontinuous metal stratum. The glass may comprise aflexible or conformable glass, such as an aluminosilicate, borosilicate,boro-aluminosilicate glass, sapphire glass, or ion-exchange-strengthenedglass. Additional layers of the card may include a printed ink layer, alaminated layer, a laser patterned layer, a coated layer, aphotolithographic layer, a printed OLED layer, an embedded electronicslayer, or a vacuum deposited layer.

Another aspect of the invention comprises a transaction card having afirst layer, a discontinuous metal stratum disposed on a first surfaceof the first layer and comprising a plurality of isolated metal featuresthat form a halftone pattern; and a contact, contactless, or dualinterface transaction module disposed in the first layer andelectrically isolated from the discontinuous metal stratum. Each of theplurality of metal features is separated from adjacent metal features byat least a predetermined minimum distance calculated to avoid bridgingof energy between adjacent halftone dots in the presence of less than apredetermined level of energy, such as the maximum field strength of acontactless transaction card reader. The first layer may comprise anon-metal layer, such as a transparent material. The halftone patternmay be perceptible to the human eye as a continuous opaque layer thathides visibility of an underlying layer, such as an underlying metallayer having a plurality of discontinuities.

According to embodiments of the aspects of the invention, thediscontinuous metal stratum may include one or more transparent areasthat permit visibility of an underlying surface or layer of the card.The underlying surface or layer visible through the transparent areaincludes another discontinuous metal stratum.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a cross-sectional illustration of a portion of an exemplaryglass layer of a transaction card having a discontinuous metal stratum.

FIG. 1B is a plan view illustration of an exemplary portion of the cardportion of FIG. 1A, illustrating isolated features on the core layer.

FIG. 1C is a cross-sectional illustration of a transaction card having adiscontinuous metal stratum on one surface and a metallized antenna onthe opposite surface.

FIG. 1D is a plan view illustration of an exemplary portion of a cardhaving a continuous metal layer interrupted by holes in the metal layer.

FIG. 2 is a cross-sectional illustration of a portion of an exemplarytransaction card embodiment having two glass layers and a discontinuousmetal stratum.

FIG. 3 is a cross-sectional illustration of a portion of an exemplaryglass layer of a transaction card having a coating disposed over thediscontinuous metal stratum.

FIG. 4 is a cross-sectional illustration of a portion of an exemplarytransaction card embodiment having two glass layers, a discontinuousmetal stratum, and a metallized antenna layer.

FIG. 5 is a cross-sectional illustration of a portion of an exemplarytransaction card embodiment having multiple glass layers and multiplediscontinuous metal strata.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIGS. 1A and 1B, portion 10 of a transaction cardcomprises a substrate 12, a discontinuous metal stratum 14 comprising aplurality of isolated features 15, and a transaction module 16. Asreferred to herein, the transaction module may be any module configuredfor conducting any type of transaction, capable of contact-only,contactless-only, or dual interface (contact and contactless)interaction with a card reader, and in particular a transaction moduleconfigured for conducting financial transactions (sometimes referred toas a “payment module”), such as are commonly found in credit cards,debit cards, and the like. Contactless modules typically use radiofrequency (RF) communications and comprise radio frequencyidentification (RFID) integrated circuits that operate in compliancewith the ISO/IEC 14443 international standard for contactless smart cardcommunications. The invention is not limited to any particular type oftransaction card, or transaction module, however.

Substrate 12 is preferably a glass layer, such as but not limited to aflexible or conformable glass, such as an aluminosilicate, borosilicate,boro-aluminosilicate glass, sapphire glass, or ion-exchange-strengthenedglass. Numerous examples of such flexible or conformable glasses areknown in the art, and are favored for their shatter-resistant propertiesand strength. Such glasses are also denser than traditional plasticlayers found in some transaction cards, and therefore lend additionalheft or weight to the overall look and feel of a card. Althoughpreferred embodiments comprise flexible or conformable glasscompositions, the term “glass” as used herein refers to any materialhaving any non-polymeric chemical composition (i.e. non-plastic),typically inorganic, and typically containing SiO2 as a primarycomponent, that is transparent or semi-transparent, including amorphousnon-crystalline compounds as well as crystalline compounds, sometimesalso referred to as “crystal.” Additionally, acceptable glass layers mayinclude glass varieties known as “safety glass,” including laminatedglass (comprising one or more layers each of glass and plastic,typically held together by an interlayer), toughened (tempered) glassand engraved glass. While glass layers having transparency orsemi-transparency may have certain advantages, embodiments of theinvention may include embodiments with cores comprising other non-metalor non-plastic materials (e.g. ceramic) that are opaque or onlytranslucent. Although depicted as a monolithic layer, the core layer maycomprise a composite of multiple material layers, including multipleglass layers of the same or different types of glass.

Discontinuous metal stratum 14 is preferably comprises a plurality ofisolated metal features 15. The term “stratum” is used herein consistentwith the Latin meaning of something “spread or laid down,” to reflectthat in at least some embodiments, the isolated metal features do notform a contiguous layer in the same way as a bulk metal layer or foillayer. In other embodiments, disclosed herein later, however, thediscontinuous metal stratum may indeed comprise a layer with an adequateamount of electrical eddy current disruption between adjacent metalregions, but may form a contiguous layer. In some embodiments, theisolated metal features are isolated from the moment of formation,whereas in others, a metal layer may be processed to create theelectrical eddy current disruption between features, which may comprisea distance of empty space that provides isolation.

Suitable metals for the metal stratum may include aluminum, silver,copper, gold, rhodium, tungsten, titanium and alloys of the foregoing,including alloys that contain nonmetallic elements (e.g. titaniumnitride), including non-metallic elements for creating a desired coloreffect, but the invention is not limited to any particular metal ormetal alloy. For example, numerous colored surface coatings in differentcolors may be obtained, e.g., via PVD, such as: gold (TiN), rose gold(ZrN), bronze (TiAIN), blue (TiAIN), black (TiAICN), as well as a darkred (ZrN). The metal features may also or instead be heat treated toobtain a desired color. Although depicted as having a round crosssection, it should be understood that the features may have any crosssection. Likewise, while depicted as having a frustoconical shape inlongitudinal section, the features may have any geometry in longitudinalsection, including hemispherical, and having round or flat tops. Theterm “isolated” is intended to mean that each metal feature is separatedfrom adjacent metal features by at least a predetermined minimumdistance “d” as depicted in FIG. 1B. Preferably, the predeterminedminimum distance between adjacent features is a distance calculated toavoid bridging of energy between adjacent halftone dots in the presenceof less than a predetermined level of energy. In embodiments in whichthe metal features are not isolated, the features otherwise have asufficient degree of electrical eddy current disruption relative to oneanother to avoid syncing of eddy currents of adjacent metal regions atthe predetermined level of energy in a way that disrupts thecommunications for processing the transaction at a desired distancebetween the card and the card reader. The predetermined energy level maycoincide with the typical maximum rated field strength of a contactlesstransaction card reader. For example, the typical energy density foundin a Point of Service (POS) terminal for contactless processing atransaction card at the extremes may include a range of 0.5-12.5 A/m²(amperes per square meter).

The plurality of isolated metal features in the discontinuous metalstratum preferably form a halftone pattern. The halftone pattern may bedefined by the plurality of metal features evenly distributed across thesurface of the card, or the plurality of metal features may have anuneven distribution, wherein the uneven distribution forms a halftoneimage. As is known in the art, halftone is a technique that uses aplurality of dots so small and spaced so closely together that the humaneye interprets the plurality of dots as a continuous-tone. The sizeand/or spacing of the halftone dots may also be varied to generate agradient-like effect between light tones and dark tones. Halftoning istypically used as a reprographic technique, such as in the field ofprinting, in which the gradient of tones between light and dark may beused to form grayscale images. Likewise, combinations of grayscaleimages printed with different color inks (e.g. Cyan, Yellow, Magenta andblack in a CYMK color scheme) in halftone patterns may be combined toform full color printed content. In traditional printing, the gradientbetween light and dark may span from lighter tones in which each printed“dot” is isolated from each adjacent dot, to darker tones in which theprinted dots are so close together that the adjacent dots of ink connectto one another with holes comprising the absence of ink being isolatedfrom one another. In embodiments of the invention in which isolationbetween the metal features is essential to minimize effects caused bythe metal stratum on RF communications, a majority or at leastsubstantial portions of metal features preferably conform ametallization pattern in which each “dot” in the halftone pattern isisolated from adjacent dots. However, in embodiments in which gradientsin tone are combined to create a visual image, at least some portions ofthe halftone image may comprise portions of the metallization pattern inwhich some of the halftone dots connect to another other. In general,however, the metallization pattern is disposed to avoid creating acontinuous path of metal within at least select areas of the card, andpreferably between an edge of the card and the periphery of the paymentmodule. A combination of a halftone pattern of discrete metal featuresin one area, and discontinuities in a bulk or foil metal in anotherarea, may also be provided.

The metal features may be deposited by any method known in the art,including but not limited to physical or chemical vapor depositionprocesses by which the dots are created directly on the glass substrate,deposition of a solid layer or a foil on the substrate and etching awaymetal from the between the remaining features, or printing, such asusing inkjet, lithographic, or additive manufacturing (i.e. 3D printing)processes. For example, in one embodiment, a photoresist may be disposedon the substrate, exposed through a mask with actinic radiation (e.g.UV) to cure the exposed portions of the photoresist, and the uncuredportions removed. Then, the metal may be deposited using a depositionprocess (e.g. CVD or PVD) that creates the metal features on thesubstrate in the areas where there is no photoresist, and deposits themetal on the photoresist where the photoresist remains. The photoresistis then removed, leaving the metal features. In the foregoing, the maskis a negative mask that allows the actinic radiation through holes inthe mask that coincide to the spaces between the metal features, so thatthe cured photoresist remains on the substrate in the areas where it isnot desired to deposit the metal features. In another process, acontinuous metal layer is disposed on the substrate, such as with a PVDor CVD process, a photoresist deposited over the metal layer, and theresist exposed to actinic radiation through a positive mask that hasholes corresponding to the metal features. The uncured photoresist isremoved, and an etching process is conducted, which etches away themetal in the areas not protected by the photoresist. The photoresist isthen removed, leaving the metal features, In still other embodiments,the metal features may be formed from continuous solid metal layer, andunwanted portions of the metal removed by focused energy, such as alaser or an e-beam (focused electron beam), leaving only the metalfeatures. In still other embodiments, the metal features may be formedby metal particles contained in a curable or sinterable resin. Inanother embodiment, dot-shaped or wire-like metal nanostructures may beprepared in an array as a self-assembled monolayer on a diblockcopolymer template, as described in Erb et al., “Uniform metalnanostructures with long-range order via three-step hierarchicalself-assembly,” Science Advances, Vol. 1, no. 10 (6 Nov. 2015),incorporated herein by reference.

Although embodiments with isolated metal features have been primarilydescribed, it should be understood that inverse designs may also providesufficient electrical eddy current disruption between metal regions topermit sufficient RF transmissivity through the discontinuous metalstratum. For example, as shown in FIG. 1D, an array of holes 12 in metallayer 15 may be coupled with one or more elongated discontinuities orslits, such as one or more lines 13, one or more of which preferablyextends to a periphery of the card or which is in communication with anon-metal area that extends to the periphery of the card. Multi-slitdesigns in a metal layer are described, generally in U.S. ProvisionalApplication Ser. No. 62/971,439, filed Feb. 7, 2020, titled “DI METALTRANSACTION DEVICES AND PROCESSES FOR THE MANUFACTURE THEREOF,”incorporated herein by reference. In another embodiment that providesopen space between metal features in which at least some of the openspace is isolated from and not in communication with adjacent openspace, a micro- or nano-mesh may be prepared and bonded to thesubstrate. Such metal mesh patterns may also benefit from the use ofmultiple slits or elongated discontinuities to break up metal regionsthat would otherwise form interconnected metal regions, and eddycurrents associated therewith, extending across a relatively largeportion of the card.

It should be understood that although in some embodiments card portion10 may comprise a freestanding card without more, in other embodimentsportion 10 may include one or more additional decorative or functionallayers not depicted in FIG. 1A, including printed layers, protectivelayers, and layers containing other functional or aesthetic featurescommon to transaction cards, including but not limited to securityfeatures such as holograms, codes (such as bar codes or QR codes),magnetic stripes, signature blocks, printed layers, embossed layers,embedded electronics, and the like. Methods for embedding electronics incards, generally, are described in U.S. application Ser. No. 16/441,363,filed Jun. 14, 2019, titled OVERMOLDED ELECTRONIC COMPONENTS FORTRANSACTION CARDS AND METHODS OF MAKING THEREOF, filed 27 Jul. 2016, andrelated applications to which priority is claimed or that claim prioritytherefrom, all of which are incorporated herein by reference. Additionallayers may also include one or more of: a printed ink layer, a laminatedlayer, a laser patterned layer, a coated layer, a photolithographiclayer, a printed OLED layer, or a vacuum deposited layer. The relativesizes of the various features as depicted in FIG. 1 (and in any of thefigures herein depicted) are not intended to be to scale.

Referring now to FIG. 1C, a card embodiment is depicted comprising cardportion 10, comprising first glass layer 12, discontinuous metal stratum14 disposed on one surface of glass layer 12, and a metallized antenna17 disposed on the opposite surface of the glass layer. Transactionmodule 16 is disposed in the first glass layer 12. In other embodiments,additional decorative or functional layers may be present in any portionof the stack, such as a protective coating 18 (preferably clear) overthe metallized antenna 17, such as UV- or thermally-cured polymericcompounds, sometimes referred to as potting compounds. The metallizedbooster antenna 17 may be transparent, such as formed from indium tinoxide (ITO). The metallized antenna 17 may be created by any methodknown in the art, including deposition of a continuous metal stratum onthe glass surface, and etching away portions of the metal to leave thedesired antenna structure. The booster antenna 17 inductively coupleswith or is physically electrically connected to the transaction module16 to improve communication performance.

Referring now to FIG. 2 , a card embodiment 20 is depicted having afirst glass layer 22, a discontinuous metal stratum 24 as describedabove, and a second glass layer 28, with a transaction module 26disposed in the first glass layer 22. The metal stratum 24 is disposedon the first glass layer 22 between the first glass layer 22 and thesecond glass layer 28. This location of the discontinuous metal stratum24 as an inner stratum sandwiched between outer layers of glass layers22, 28 protects the metal stratum 24 from wear and tear. In otherembodiments, additional decorative or functional layers may be presentin any portion of the stack. Although the transaction module 26 isdepicted as disposed entirely in the first glass layer 22, otherembodiments may include the transaction module 26 extending through thediscontinuous metal stratum 24 into the second glass layer 28. While thetransaction module 26 is depicted as having a top surface flush with anouter surface of the card 20, such as is typical for contact or dualinterface modules, a contactless-only module may be disposed entirelybeneath the top surface of the card 20. Exemplary cards having thedesigns as described herein may include cards with transaction modulesthat are contact only, contactless only, or dual interface (DI).

Referring now to FIG. 3 , card embodiment 30 has a first glass layer 32,a discontinuous metal stratum 34 as described above, a protective layer37, and a transaction module 36 disposed in the first glass layer 32with a top surface flush with the top surface of the protective layer37. The protective layer 37 as depicted fills gaps between the metalfeatures 35 and is disposed over the discontinuous metal stratum 34. Itshould be understood that in some embodiments, the protective layer 37may fill gaps between the metal features 35 but not extend as a coveringover the discontinuous metal stratum 34, and in other embodiments, theprotective layer 37 may extend over the discontinuous metal stratum 34but not between the metal features 35. In still other embodiments, theprotective layer 37 may only partially fill gaps between the metalfeatures 35. Protective layer 37 is preferably a non-metal layer thatacts as an electrical isolator and insulator, and the effects of theisolation and insulation may enable a smaller spacing between featureswith less interference with RF communications than without theisolation/insulation layer. In other embodiments, additional decorativeor functional layers may be present in any portion of the stack. To theextent necessary or desired, the protective layer 37 may comprise anIR-blocking compound, particularly in any implementations that benefitfrom such a blocker in order to confirm to card ATM standards. Forexample, the embodiment depicted in FIG. 3 may include a metallizedantenna layer as depicted in FIG. 1C, with or without a protective layer37 over the metallized antenna layer.

Referring now to FIG. 4 , card embodiment 40 includes a first glasslayer 42, a discontinuous metal stratum 44, a payment module 46 disposedin the first glass layer 42, a second glass layer 48, and a metallizedantenna layer 47 disposed over the second glass layer 48. Thediscontinuous metal stratum 44 and the metallized antenna 47 are bothdisposed on the inner surfaces of the respective first and second glasslayers 42, 48 facing one another, and may include a non-metal layer 45(e.g. a PVC, PET, or other polymer layer and/or an adhesive layer)disposed between the discontinuous metal stratum 44 and the metallizedantenna 47 to insulate and isolate the antenna layer 47 from thediscontinuous metal stratum 44. Layer 49, on the outer surface of thesecond glass layer 48 may comprise a printed ink layer, a laminatedlayer, a laser patterned layer, a coated layer, a photolithographiclayer, a printed OLED layer, or a vacuum-deposited layer. Additionaldecorative or functional layers may also be present in any portion ofthe stack. In some embodiments, the laminated layer may be a metallayer, preferably an RF invisible or nearly invisible metal layer, suchas an otherwise continuous metal layer having one or morediscontinuities in the nature of elongated slits, as described in U.S.Prov. App. Ser. No. 62/971,439, referenced above.

Although not limited to any particular constructions, the metal features15 are preferably disposed on the glass layer with a density of at least32 dots per inch (DPI) (12.6 dots per centimeter (dpcm)), and may be ina range of 32 to 6.5E14 DPI (12.6-2.56E14 dpcm)(the current technicalupper limit of e-beam lithography), and more preferably in a range of480-4800 DPI (190-1900 dpcm), in embodiments in which the halftonepattern is intended to give the discontinuous layer an opaque visualappearance. Notably, the term DPI (or dpcm) typically relates to thenumber of dots per unit of linear horizontal measure, whereas LPI (orlines per inch) typically relates to the number of horizontal lines perunit of linear vertical measure in printing processes. Many printingprocesses have different capabilities in one direction relative to theother. As used herein, the metrics DPI or dpcm are intended to refer toeither or both horizontal or vertical dimensions, with horizontalreferring to the relatively longer dimension of a card, and verticalreferring to the relatively shorter dimension of a card.

Other embodiments may include features 15 with a size large enough to bevisually perceptible to the human eye to form an intended pattern, whichmay include geometric arrangements of dots, or visual patterns formedusing pointillist artistic techniques that create an image. Features 15may be provided in combinations of different types of metal, or metaland non-metal, with the different types of features having differentcolor tones for graphical/artistic purposes. For example, dots may rangefrom a metal with a silver tone (e.g. Aluminum) to a metal with a blacktone (e.g. black ruthenium or black nickel) to create a 2-tone graphic.

The use of more than two different color tones may be used to createvisual images with the different tones, including with tones to createor approximate 4-color printed images. For example, a color palate ofmetallic substances, such as ZrN (red), TiAIN (blue), TiN (gold), andTiAICN (black) may be used to approximate the corresponding separationsof a CMYK image. In combinations of metal and non-metal, the non-metalmay comprise, for example, an ink with the same tone as the metal, sothat visual effects incorporating darker tones may be formed bynon-metal features in order to permit the metal features to remain at apredetermined spacing. In other embodiments, non-metal inks may be usedin combination with a metal halftone pattern to fill in for one or morecolors in a 4-color separation. For example, a 4-color image may beformed of a combination of features in yellow and black formed from aconductive (or relatively more conductive) metal (e.g. gold for yellowand black nickel for black) and magenta and cyan formed fromnon-conductive (or relatively less conductive) ink. In otherembodiments, however, darker tones and lighter tones may be formedsolely by metal features, with some areas in relatively darker tonescomprising metal halftone dots that are not entirely separated from oneanother within the dark tonal area, and relatively lighter tonal areasin which the plurality of metal halftone dots are all separated from oneanother.

Relatively lighter and darker areas may be formed by FM or AM dotfrequency modulation, wherein FM modulation entails using the same sizedot throughout a visual pattern, wherein changes in spacing of the dotsto form changes in tone, and AM modulation entails using different sizedots at a same relative spacing on center to form changes in tone.Combinations of AM and FM modulation, such as are known in the field ofhalftone printing, may also be used, such as in which AM modulation isused for one part of the tonal range and FM modulation used for another.

Although discussed primarily herein with respect to use of a pluralityof electrically insulated features on a glass layer, it should beunderstood that the methods as described herein may be performed on anytype of substrate, including non-glass transparent (or translucent)polymer substrates, such as but not limited to polyethyleneterephthalate (PET), including but not limited to high-density polyester(HDPE), low density polyester (LDPE), and glycol-modified polyester(PETG)), polycarbonate, acrylic (polymethlamethacrylate), butyrate(cellulose acetate butyrate), glass-reinforced epoxy laminate material(e.g. FR4), polypropylene, and polyether ether ketone (PEEK), as well asnon-transparent/non-translucent substrates, including ceramic. In someembodiments, it may be desirable to use a halftone pattern as describedherein to hide underlying layers, such as layers with discontinuities,such as described in U.S. Provisional Patent Application Ser. No.62/971,439, titled DI METAL TRANSACTION DEVICES AND PROCESSES FOR THEMANUFACTURE THEREOF, and in U.S. application Ser. No. 15/928,813, filedon Mar. 22, 2018, (status: pending), which claims priority to U.S.Application No. 62/623,936, filed Jan. 30, 2018, both titled DICAPACITIVE EMBEDDED METAL CARD, all of the foregoing incorporated hereinby reference for all purposes.

Embodiments may comprise a combination of a first transparent layerhaving a discontinuous metal stratum comprising isolated metal featuresand a second transparent layer comprising a discontinuous metal stratumcomprising a metal layer with a plurality of discontinuities. Cards mayalso include one or more transparent layers with a discontinuous stratumcomprising isolated metal features in one area of the stratum andcontinuous metal region with a plurality of discontinuities in anotherarea. Some regions of a transparent layer may have an absence of metalto permit transparency to another layer of the card (includingtransparency in a first metal stratum on a first surface of the layerthat permits visibility of a second metal stratum on a second surface ofthe layer). Multiple transparent layers, each with correspondingdiscontinuous strata covering less than all of one or more surfaces ofeach layer, may include areas of transparency that provide visibility toan underlying surface or layer in a combination of patterns that createto create a 3-dimensional optical effect. Thus, for example, as depictedin FIG. 5 , card 50 may have a first transparent layer 58, in whichtransaction module 56 is embedded. A second transparent layer 52 mayhave a first discontinuous metal stratum 54 disposed on a first surfacethereof, and an absence of metal in area 51, that permits visibility ofsecond discontinuous metal stratum 53 on the opposite surface of layer52. Although not shown, a further transparent (non-metallized) area instratum 53 may be present that permits visibility to an additionalunderlying layer (not shown). In embodiments having transparentportions, the transparent portions may be rendered sufficientlynon-transmissive (i.e. to meet the ISO/IEC 10373 standard) for blockingthe infrared (IR) wavelengths used by card-sensing devices (e.g.automatic teller machines (ATMs), which typically use LEDs with 860 or950 nm wavelengths). IR blocking capabilities may be conferred byadditives in the transparent materials that form the substrate (oranother layer), a coating, or a layer having IR-filtering properties.

Although the invention is illustrated and described herein withreference to specific embodiments, the invention is not intended to belimited to the details shown. Rather, various modifications may be madein the details within the scope and range of equivalents of the claimsand without departing from the invention.

1. A transaction card, comprising: at least a first glass layer; adiscontinuous metal stratum disposed on a first surface of the glasslayer and having a desired degree of electrical eddy current disruption;and a contact, contactless, or dual interface transaction moduledisposed in the first glass layer and electrically isolated from thediscontinuous metal stratum.
 2. The transaction card of claim 1, whereindiscontinuous metal stratum comprise a metal layer having a plurality ofdiscontinuities.
 3. The transaction card of claim 2, wherein theplurality of discontinuities form a pattern.
 4. The transaction card ofclaim 2, wherein the plurality of discontinuities are configured toavoid synchronization of eddy currents of adjacent metal regions in thepresence of less than a predetermined level of energy.
 5. Thetransaction card of claim 1, wherein discontinuous metal stratumcomprise a plurality of isolated metal features.
 6. The transaction cardof claim 5, wherein the plurality of isolated metal features form apattern.
 7. The transaction card of claim 5, wherein each of theplurality of metal features is separated from adjacent metal features byat least a predetermined minimum distance.
 8. The transaction card ofclaim 7, wherein the predetermined minimum distance is a distancecalculated to avoid bridging of energy between adjacent halftone dots inthe presence of less than a predetermined level of energy.
 9. Thetransaction card of claim 4, wherein the predetermined level of energycomprises a maximum field strength of a contactless transaction cardreader.
 10. The transaction card of claim 3, wherein the patterncomprises a halftone pattern.
 11. The transaction card of claim 10,wherein the halftone pattern comprises the plurality of metal featuresor discontinuities evenly distributed across the first surface of thecard.
 12. The transaction card of claim 10, wherein the halftone patterncomprises the plurality of metal features, plurality of discontinuities,or a combination thereof having an uneven distribution, wherein theuneven distribution forms a halftone image.
 13. The transaction card ofclaim 10, wherein the halftone pattern includes a combination of metalfeatures and non-metal features.
 14. The transaction card of claim 10,wherein the halftone pattern forms is perceptible to the human eye as acontinuous opaque layer.
 15. The transaction card of claim 1, furthercomprising a second layer of glass.
 16. The transaction card of claim15, wherein the discontinuous metal stratum is disposed between thefirst glass layer and the second glass layer.
 17. The transaction cardof claim 15, further comprising a metallized booster antenna disposed ona surface of the second glass layer, the metallized booster antennacoupled to or configured to couple to the transaction module andelectrically isolated from the discontinuous metal stratum on the firstlayer of glass.
 18. The transaction card of claim 17, wherein themetallized booster antenna is disposed on an inner surface of the secondglass layer arranged between the first glass layer and the second glasslayer.
 19. The transaction card of claim 17, further comprising anelectrically isolating layer disposed between the discontinuous metalstratum and the metallized booster antenna.
 20. The transaction card ofclaim 19, wherein the electrically isolating layer comprises a non-metallayer.
 21. The transaction card of claim 17, wherein the metallizedbooster antenna is disposed on an outer surface of the second glasslayer facing away from the first glass layer.
 22. The transaction cardof claim 21, further comprising a protective coating over the metallizedantenna.
 23. The transaction card of claim 17, wherein the metallizedbooster antenna is transparent.
 24. The transaction card of claim 23,wherein the metallized antenna comprises indium tin oxide (ITO).
 25. Thetransaction card of claim 1, wherein the discontinuous metal stratum isdisposed on a first outer surface of the first glass layer.
 26. Thetransaction card of claim 25, further comprising a metallized boosterantenna disposed on a second outer surface of the first glass layer, themetallized booster antenna coupled to or configured to couple to thetransaction module.
 27. The transaction card of claim 5, furthercomprising an electrical isolating material disposed between adjacentmetal features in the discontinuous metal stratum.
 28. The transactioncard of claim 1, further comprising an electrical isolating materialdisposed over the discontinuous metal stratum.
 29. The transaction cardof claim 1, wherein the first layer of glass comprises a flexible orconformable glass.
 30. The transaction card of claim 15, wherein one orboth of the first layer of glass and the second layer of glass comprisesa flexible or conformable glass
 31. The transaction card of claim 29,wherein the flexible glass comprises an aluminosilicate, borosilicate,boro-aluminosilicate glass, sapphire glass, or ion-exchange-strengthenedglass.
 32. The transaction card of claim 1, wherein a second surface ofthe first glass layer is in contact with an additional layer selectedfrom the group consisting of: a printed ink layer, a laminated layer, alaser patterned layer, a coated layer, a photolithographic layer, aprinted OLED layer, an embedded electronics layer, or a vacuum depositedlayer.
 33. The transaction card of claim 1, further comprising one ormore additional layers.
 34. The transaction card of claim 33, whereinthe one or more additional layers is selected from the group consistingof: a printed ink layer, a laminated layer, a laser patterned layer, acoated layer, a photolithographic layer, a printed OLED layer, anembedded electronics layer, or a vacuum deposited layer.
 35. Atransaction card, comprising: a first layer; a discontinuous metalstratum disposed on a first surface of the first layer and comprising aplurality of isolated metal features that form a halftone pattern; and acontact, contactless, or dual interface transaction module disposed inthe first layer and electrically isolated from the discontinuous metalstratum.
 36. The transaction card of claim 35, wherein each of theplurality of isolated metal features is separated from adjacent metalfeatures by at least a predetermined minimum distance calculated toavoid bridging of energy between adjacent isolated metal features in thepresence of less than a predetermined level of energy.
 37. Thetransaction card of claim 36, wherein the predetermined level of energycomprises a maximum field strength of a contactless transaction cardreader.
 38. The transaction card of claim 35, wherein the first layercomprises a non-metal layer.
 39. The transaction card of claim 38,wherein the non-metal layer comprises a transparent material.
 40. Thetransaction card of claim 38, further comprising an underlying layerdisposed beneath the non-metal layer, wherein the halftone pattern isperceptible to the human eye as a continuous opaque layer that hidesvisibility of the underlying layer.
 41. The transaction card of claim40, wherein the underlying layer comprises a metal layer.
 42. Thetransaction card of claim 41, wherein the underlying metal layercomprises a plurality of discontinuities.
 43. The transaction card ofclaim 1, wherein the discontinuous metal stratum includes one or moretransparent areas that permit visibility of an underlying surface orlayer of the card.
 44. The transaction card of claim 43, wherein theunderlying surface or layer visible through the one or more transparentareas includes another discontinuous metal stratum.